This invention relates to a new antibiotic complex which has been isolated by fermentation of a new strain of the microorganism Streptomyces hirsutus. The new antibiotic complex has been designated CP-61,884, and it has been shown to contain three major components. Chemically, these major components are new members of the macrolide class of antibiotics.
The three major components of antibiotic complex CP-61,884 are neutral macrolides, containing a 16-membered lactone ring, and they can be compared to chalcomycin. See further, the Merck Index, 10th Edition, Merck & Co., Inc., Rahway, N.J., U.S.A., 1983, Abstract No. 1990 (page 283).